Affects a widely used frontend framework (Angular); could enable cache poisoning on SSR affecting many apps.
CVE-2026-54266
Hash collision in Angular SSR cache can overwrite responses via crafted URL.
Is CVE-2026-54266 being exploited?
Not confirmed. CVE-2026-54266 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.13% probability of exploitation in the next 30 days.
How severe is CVE-2026-54266?
CVE-2026-54266 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-54266?
Yes. A fix has been recorded for CVE-2026-54266. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-54266 affect?
CVE-2026-54266 affects Angular (SSR TransferState). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-54266?
Upgrade to fixed Angular versions (22.0.1+, 21.2.17, 20.3.25+)
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Cache poisoning in SSR TransferState allows overwriting cached responses, risking data exposure or altered pages.
Patch when possible
- affected>= 22.0.0-next.0 and < 22.0.1
- affected>= 21.0.0-next.0 and < 21.2.17
- affected>= 20.0.0-next.0 and < 20.3.25
- affected<= 19.2.25
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.